EP4277762A1

EP4277762A1 - Improved method for manufacturing a part by additive manufacturing

Info

Publication number: EP4277762A1
Application number: EP22702757.0A
Authority: EP
Inventors: Mickaël VOIRON; Thomas GRICOURT; Nicolas OVAERE; Matthieu VIAL
Original assignee: Safran SA
Current assignee: Safran SA
Priority date: 2021-01-18
Filing date: 2022-01-11
Publication date: 2023-11-22
Also published as: US20240066601A1; FR3118892A1; CN116940427A; WO2022153004A1; FR3118892B1

Abstract

The invention relates to a method for manufacturing an aeronautical part by additive manufacturing, the part to be manufactured extending around a central axis (X) and comprising at least two walls (20, 42) angled with respect to one another and connected to one another by means of at least one connection section (S) comprised in a connection plane (R) perpendicular to the central axis (X), the method comprising: - providing a digital model (1) of the part to be manufactured, - orienting the digital model (1) with respect to a vertical construction direction (Z) of the part so that the central axis (X) of the part has an angle β of between 0.1° and 1°, preferably between 0.3° and 0.8°, with respect to the construction direction (Z), - manufacturing the part by additive manufacturing from the digital model (1) obtained in the orientation step.

Description

Title of the invention: IMPROVED PROCESS FOR MANUFACTURING PARTS BY ADDITIVE MANUFACTURING

Technical area

[0001] This presentation concerns a process for manufacturing parts by additive manufacturing, making it possible in particular to improve the surface condition of the parts obtained. Such an additive manufacturing process is particularly suitable for manufacturing complex parts, intended in particular for the aeronautical field.

Prior technique

[0002] It is now known, in the aeronautical field in particular, to use additive manufacturing methods for the production of certain parts whose geometry is fine or complex.

[0003] A classic example of additive manufacturing is manufacturing by melting or sintering powder particles using a high-energy beam. Among these high energy beams, we can mention in particular the laser beam and the electron beam.

[0004] By "selective laser melting", in English "Selective Laser Melting" (SLM), also known as the "Laser Beam Melting" (LBM) process, is meant a process whose main characteristics are recalled below. after, with reference to FIG. 9 illustrating a conventional device for manufacturing a part by selective melting or selective sintering of powder beds by means of a laser beam.

Is deposited, for example using a spreading tool 120 (for example a roller, or a scraper), a first layer 110a of powder of a material on a construction plate 121 (it can it may be a plate alone or surmounted by a solid support, part of another part or a support grid used to facilitate the construction of certain parts). This powder is decanted from a feed tray 122 during a forward movement of the roller 120 then it is scraped, and possibly slightly compacted, during one (or more) return movement(s) of the roller 120. The powder is made up of particles 1 1 1. The excess powder is collected in a recycling bin 123 located adjacent to the build bin 124 in which the build plate 121 moves vertically.

[0007] A generator 130 of laser beam 131 is also used, and a control system 132 capable of directing this beam 131 onto any region of the build plate 121 so as to scan any region of a layer. of powder previously deposited. The shaping of the laser beam 131 and the variation of its diameter on the focal plane are done respectively by means of a beam expander or focusing system 133 and a "Beam Expander" 134, the whole constituting the system optical.

Then, a region of this first layer 110a of powder is brought, by scanning with a laser beam 131, to a temperature above the melting temperature of this powder.

[0009] This type of additive manufacturing process can use any high-energy beam instead of the laser beam 131, and in particular an electron beam, as long as this beam is sufficiently energetic to melt the powder particles and part of the material on which the particles sit.

This scanning of the beam is carried out for example by a galvanometric head forming part of a control system 132. For example, this control system comprises at least one adjustable mirror 135 on which the laser beam 131 is reflected before reaching a layer of powder, each point of the surface of which is always located at the same height with respect to the focusing lens, contained in the focusing system 134, the angular position of this mirror being controlled by a galvanometric head so that the beam laser scans at least a region of the first layer of powder, and thus follows a pre-established part profile. To do this, the galvanometric head is ordered according to the information contained in the base of data from the computer tool used for the computer-aided design and manufacture of the part to be manufactured.

[0011] Thus, the powder particles 1 1 1 of this region of the first layer 100a are melted and form a first element 112a in one piece, integral with the construction plate 121. At this stage, it is also possible to sweep several independent regions of this first layer with the laser beam to form, after melting and solidification of the material, several first elements 120a disjointed from each other.

[0012] The build plate 121 is lowered by a height corresponding to the thickness of the first layer of powder 110a (20 to 100 μm and in general from 30 to 50 μm).

A second layer 110b of powder is then deposited on the first layer 110a and on this first integral or consolidated element 112a, then a region of the second layer 1 is heated by exposure to the laser beam 131 10b which is situated partially or completely above this first integral or consolidated element 112a in the case illustrated in FIG. 9, such that the powder particles of this region of the second layer 110b are fused with at least a part of the element 112a and form a second integral or consolidated element 112b, the set of these two elements 112a and 112b forming, in the case illustrated in FIG. 9, a single block.

[0014] Such an additive manufacturing technique therefore ensures excellent control of the geometry of the part to be manufactured and makes it possible to produce parts of great complexity.

[0015] However, during the production of parts with complex geometry, in particular cylindrical parts such as bearing supports, certain walls of the part are inclined with respect to each other, and are connected to each other at the level of a curved connection zone, for example in the arc of a circle. Although the connection section between these walls is thin in the radial direction, the surface occupied by this section can be large insofar as it can extend over the entire circumference of the room. However, during the fusion of the layer making it possible to connect these walls together, the connection section is found in a configuration

"downskin", that is to say temporarily overhanging, or even without any support other than the volume of unsolidified powder located below, and therefore present a risk of subsidence or collapse. This "downskin" configuration also involves different parameters than the parameters used for the previous layers, called standard core layers.

[0016] Consequently, at the time of layering, during the passage of the scraper (or roller), the presence of this subsidence involving an irregularity and extending over the entire connection section, creates a "wall" effect resulting in a slight vibration of the scraper. This vibration can give rise to a jump on the adjacent surface of the part, in particular the outer skin, and therefore to a surface defect. This defect, which can be characterized by 3D optical microscopy, can result in a jump that can reach a height of around 250 pm, in the case of a layer thickness of 40 pm.

[0017] These defects can be problematic insofar as they are difficult to remove, in particular on the complex surfaces of the parts mentioned above. In addition, they can be the source of local stress concentrations which can be detrimental from the dimensioning point of view of the part.

[0018] There is therefore a real need for a process for manufacturing parts by additive manufacturing, making it possible to overcome at least some of the aforementioned drawbacks, and thus to improve the surface condition of the parts obtained.

Disclosure of Invention

This presentation relates to an aeronautical part manufacturing process by additive manufacturing, the part to be manufactured extending around a central axis and comprising at least two walls inclined with respect to each other and connected between they via at least one connection section included in a connection plane perpendicular to the central axis, the method comprising:

- the supply of a digital model of the part to be manufactured, - the orientation of the digital model with respect to a vertical construction direction of the part so that the central axis of the part has an angle P between 0.1° and 1°, preferably between 0, 3° and 0.8° in relation to the direction of construction,

- manufacturing of the part by additive manufacturing from the digital model obtained at the orientation stage.

[0020] In this presentation, by direction of construction, we understand the direction in which the part is built, that is to say in which the layers of powder, or manufacturing layers, are stacked on top of each other. . For example, when the part is manufactured on a build plate, the build direction corresponds to a direction orthogonal to said build plate, and is therefore vertical.

[0021] In addition, in this presentation, the terms "axial", "radial", "inner", "outer", "circumferential" and their derivatives are defined with respect to the central axis of the part. The terms “above” and “below” are understood according to the direction of construction.

[0022] All the elements constituting the part, in particular the two walls inclined with respect to each other, are manufactured in one block and from the same material by additive manufacturing. The "connection section" between the two walls inclined with respect to each other is understood as being, during additive manufacturing, the first layer of material making it possible to make the junction between these two walls.

[0023] In other words, at layer n of the additive manufacturing, the two walls are spaced apart by a thin gap. The following n+1 layer makes it possible to deposit and merge the material making it possible to fill this interstice and thus to connect the two walls together. Thus, the connecting section is the portion of this layer n+1 making it possible to fill this interstice existing at layer n. This connection section therefore extends radially along a dimension corresponding to the width of the gap, and circumferentially around the central axis, when the connection section is curved. [0024] As soon as this connection section is formed at the n+1 layer, the subsequent layers are formed in one piece, bearing in particular on this connection section, to form the junction zone between the two walls. . Nevertheless, the first layer making it possible to join these walls, that is to say the connection section, does not rest on any solid layer, other than the volume of non-solidified powder situated below.

[0025] According to the present presentation, tilting the central axis of the part by an angle P with respect to the direction of construction during the model orientation step also makes it possible to tilt the same angle 0 the connecting plane including the connecting section. The angles 0 of inclination defined above are sufficient to allow the connection section to be formed not in one layer, but in several layers, in other words in several passages of the scraper. Preferably, the number of layers necessary to form the connection section is between 10 and 40.

The fact of forming the connection section in several layers makes it possible to limit, at each of these layers, the cantilevered surface or without any other support than the volume of unsolidified powder located below, thus limiting the subsidence phenomenon. Thus, with each passage of the scraper necessary for the formation of the connecting section, the cantilevered surface encountered by the scraper will be less, and the vibrations generated on the latter will therefore be limited. Consequently, this inclination makes it possible to limit or even eliminate the presence of a jump on the final part, thus improving the surface condition of the latter.

[0027] In some embodiments, the part to be manufactured is axisymmetric around the central axis.

[0028] In some embodiments, the connection section extends along an arc of a circle centered around the central axis.

[0029] Given this shape, most of the elements constituting the part, in particular the walls inclined between them, are also axisymmetric. Therefore, the connection section between these inclined walls has a circular shape around the central axis of the piece. The inclination of the part makes it possible, during manufacture, to form this connection section in several layers, in other words, to close the circular gap existing between the two walls, in several passages of the scraper.

[0030] In certain embodiments, the step of orienting the digital model comprises the addition to the digital model of a wedge of inclination between a horizontal construction plane and a plane comprising a lower end of the part to be manufactured. , so as to tilt the central axis by the angle p with respect to the vertical construction direction.

By construction plane is meant a plane orthogonal to the construction direction and substantially parallel to the construction plate. Tilting the plane comprising the lower end of the part to be manufactured with respect to the horizontal construction plane, by means of the tilting wedge, makes it possible to tilt the whole of the part by an angle 0, without modifying its geometry.

[0032] In some embodiments, the tilt wedge is made of the same material as the part to be manufactured, during additive manufacturing.

[0033] In other words, the tilt wedge is an addition of material to the lower end of the part, making it possible, during manufacture, to orient the central axis of the part at an angle 0 relative to construction direction. It is therefore possible to improve the surface condition of the final part by simply adding material below the part, without modifying its overall geometry.

[0034] In some embodiments, the tilt wedge is configured such that, in the plane comprising the lower end of the workpiece, a first radial end of the workpiece has an elevation £ with respect to at a second radial end opposite the first radial end.

The elevation £, allowing the part to be tilted at an angle P, is low, preferably from a few tenths of a millimeter to 20 mm for example. It is therefore possible to improve the surface condition of the final part by simply adding a small quantity of material below the part, thus limiting in particular the costs incurred.

In some embodiments, the part to be manufactured comprises a substantially cylindrical outer casing, the outer casing comprising the lower end and the first and the second radial end, the first and the second radial end being diametrically opposite the one relative to the other.

[0037] By "substantially cylindrical", it is understood that the inner envelope has the shape of a cylinder, or a shape similar to that of a cylinder, despite the presence of local irregularities, for example local thinnings of its section or the presence of fastening means. It is thus possible to tilt the part by the angle 0 by simply raising a radial end of the external envelope by the height s.

[0038] In certain embodiments, £=Dxarctan(P), where D is the diameter of the external envelope of the part to be manufactured.

It is thus possible, for a given value D of diameter of the external envelope, and therefore of diameter of the part, to determine the elevation value £ necessary, to obtain a predetermined inclination 0. It will be noted that the angle P can be predetermined according to the number of layers desired, necessary to connect the two inclined walls with respect to each other.

[0040] In certain embodiments, the method comprises, after the manufacturing step, a step of removing the tilting wedge, in which the tilting wedge having been used to tilt the part during manufacturing of it is removed in order to obtain the final piece.

[0041] The tilt wedge is thus a temporary alteration of the geometry of the part, serving only to tilt the central axis of the latter during manufacture. Once the inclination wedge has been removed, the part obtained thus has the desired geometry, the surface finish of the final part being also improved.

[0042] In some embodiments, the tilt wedge is removed by machining. [0043] In other words, a radial end of the lower end of the part obtained is machined over a height corresponding to the elevation s, to remove the portion corresponding to the tilt wedge, in other words to flatten and level the lower end of the room. In this way, after machining, when the lower end of the part is placed on a horizontal support, the central axis of the part is vertical, and is no longer inclined.

[0044] In certain embodiments, the part to be manufactured is a turbojet engine bearing support.

Brief description of the drawings

The invention and its advantages will be better understood on reading the detailed description given below of various embodiments of the invention given by way of non-limiting examples. This description refers to the pages of appended figures, on which:

[0046] [Fig. 1] Figure 1 is a side view of a first example of a digital model of a part to be manufactured by the method of the invention,

[0047] [Fig. 2] Figure 2 is a sectional view of the model of Figure 1, along a section plane A,

[0048] [Fig. 3] Figure 3 shows a detailed view of the sectional view of Figure 2, illustrating a connection section between two inclined walls of the part to be manufactured,

[0049] [Fig. 4A-4B] Figures 4A and 4B represent a top view of the part of Figure 3, with two successive layers of additive manufacturing,

[0050] [Fig. 5] Figure 5 represents in a simplified way the model of figure 1, during the stage of orientation of the digital model of the part,

[0051] [Fig. 6A-6D] Figures 6A to 6D show, in a top view of the part, the formation of a connection section between two inclined walls, at successive layers of additive manufacturing,

[0052] [Fig. 7] Figure 7 is a diagram representing the different steps of the method of the invention, [0053] [Fig. 8] Figure 8 is a side view of a second example of a digital model of a part to be manufactured by the method of the invention,

[0054] [Fig. 9] Figure 9 shows an overview of an additive manufacturing device by selective melting of powder beds.

Description of embodiments

A first example of an embodiment of the invention will be explained in the following description, with reference to Figures 1 to 7. It will be noted that in the rest of the presentation, the direction of construction Z is the direction in which the part is built, that is, in which the powder layers, or build layers, are stacked on top of each other. The construction direction Z is therefore a direction orthogonal to the construction plane P, including in particular the construction plate, on which the part is intended to be manufactured. In addition, in the rest of the description, the terms "axial", "radial", "lateral", "interior", "exterior", "above" or "below" and their derivatives are defined with respect to the central axis X of part 1 to be manufactured.

In this example, the part to be manufactured is a bearing support, intended to be used in a turbomachine engine, in particular at the level of the engine exhaust casing. The turbomachine output bearing support can in particular support the bearing of the rotatable shaft coupling the high pressure compressor and a high pressure turbine. Figure 1 shows a side view of the part. More specifically, Figure 1 is a side view of the digital model 1 of the part to be manufactured. In the rest of the presentation, for convenience, the digital model of the part will simply be called "part 1". Part 1 is axisymmetric around a central axis X. The construction plane P corresponds to a horizontal plane, and represents the construction plate on which part 1 is intended to be manufactured.

[0057] A section plane A includes the central axis X, and is perpendicular to the construction plane P. Figure 2 shows a sectional side view of the part 1 illustrated in Figure 1, in the section plane A, making it possible to illustrate various elements constituting the part 1 . Exhibit 1 notably includes a external envelope 10 cylindrical, or substantially cylindrical. A lower end 12 of the outer casing 10 is included in a plane B.

A flange 20, of frustoconical shape, is fixed to the outer casing 10, inside the latter. The flange 20 is configured to carry, inside it, a plurality of support portions 30, 40, 50, each having a cylindrical internal face. The diameters of each of these cylindrical internal faces are different from each other. These support portions 30, 40, 50 are intended to support rolling bearings making it possible to guide the shafts of the turbojet engine in rotation.

These support portions 30, 40, 50 are each carried by the flange 20, via a junction portion 32, 42, 52 respectively. It will be noted that each of these elements (the flange 20, the support portions 30, 40, 50, the junction portions 32, 42, 52) is axisymmetric around the central axis X. Each of the junction portions 32, 42 , 52 is connected to an internal face of the flange 20 at a connection zone, the connection zones being located by the circles in FIG. 2. The wall of the flange 20 is inclined with respect to the central axis X, at an angle of between 40° and 60° for example. The walls of the junction portions 32, 42, 52 are also inclined with respect to the central axis X, at an angle opposite to that of the wall of the flange 20, and comprised between 40° and 60° for example. Thus, each of the junction portions 32, 42, 52 is inclined with respect to the wall of the flange 20.

[0060] Figure 3 shows a detailed view of the part of Figure 2, at the connection between the junction portion 42, and the flange 20. A hollow fixing cylinder 22, for fixing the part 1 to an element of the turbojet, is also visible. The view of FIG. 3 represents the part 1 during additive manufacturing, just after the deposition and melting of the layer of powder during which the connection section S is formed. The connecting section S is the first layer of material making it possible to fill in the gap I existing between the two walls at the previous layer (FIG. 4A) and to make the junction between the connecting portion 42 and the flange 20. The connecting section connection S is included in a connection plane R perpendicular to the central axis X. Furthermore, the connecting section S extends in an arc of a circle around the central axis X.

[0061] FIG. 4A represents a view from above of the section Sn between the junction portion 42 and the flange 20 at a stage n, that is to say at a layer n of the additive manufacturing, just before the material for connecting said junction portion 42 and said flange 20, is formed. In other words, at this stage, the actual connection section does not yet exist, and the junction portion 42 and said flange 20 are spaced radially by a thin gap I, between a few hundredths of a millimeter to 1 mm. approximately, for example 0.4 mm.

[0062] FIG. 4B represents the connection section Sn+1 between the junction portion 42 and the flange 20 at a step n+1, that is to say at an n+1 layer of additive manufacturing, in which the material for connecting said junction portion 42 and said flange 20 is formed. In the absence of orientation of the model, a single layer is therefore necessary (layer n+1) to close the gap I existing between the junction portion 42 and the flange 20 at layer n. According to this configuration, the material making it possible to close this interstice I is not formed on any existing layer, other than the unfused powder arranged below. In other words, the material of none of the layers formed in the previous steps makes it possible to support the connection section Sn+1 during its formation. Although the connecting section Sn+1 is formed from the same material as the connecting portion 42 and said flange 20, the hatchings representing the connecting section Sn+1 in FIG. 4B are different from those of the walls 20, 42, indicating the presence of local subsidence on this section.

The method according to the invention described below overcomes this drawback.

A first step makes it possible to provide a digital model of the part 1 to be manufactured (step S1), described previously. A step of orientation of this digital model is then carried out (step S2). [0065] During this step, a tilt wedge 80 is added to the digital model, so as to be placed, during the manufacture of the part 1, between the horizontal construction plane P, on which the part 1 is manufactured, and the plane B comprising the lower end 12 of the part 1, more precisely of the outer casing 10. In other words, during manufacture, the lower end 12 of the outer casing 10 of part 1 does not rest directly on the construction plane P, given the presence of the tilt wedge 80 inserted between the plane B and the construction plane P.

The tilt wedge 80 comprises a first end 81 intended to rest horizontally on the construction plane P, and a second end 82 inclined with respect to the first end 81. The lower end 12 of the outer casing 10 rests on the second end 82 of the tilt wedge 80, such that the part 1 itself has an inclination with respect to the construction plane P. external casing 10 having a cylindrical shape with an X axis, the inclination wedge 80 itself has a cylindrical shape with an Z axis, the top of which (the second end 82) is inclined with respect to the base (the first end 81).

According to a side view of part 1 (Figure 5), the tilt wedge 80 has the shape of an inclined ramp. Given this configuration, the presence of the tilt wedge 80 makes it possible to tilt the plane B comprising the lower end 12 of the outer envelope 10 of the part 1, by an angle P with respect to the construction plane P. Therefore, the central axis X is also inclined by an angle P with respect to the construction direction Z.

According to this configuration, a first radial end 14 of the part 1, in the plane B comprising the lower end 12, is raised by a height of elevation £ with respect to a second radial end 16, diametrically opposite to the first radial end 14, such that £=Dxarctan(P), where D is the diameter of the outer casing 10, in particular of the lower end 12 of the part 1 to be manufactured. The angle of inclination θ and the height of elevation ε may vary depending on the diameter D of the part 1 to be manufactured. For example, for a diameter D of 400 mm, £ can be between 0.5 and 5 mm, and P can be between 0.1° and 1°. After the addition of the inclination wedge 80 to the digital model, the part 1 is manufactured by additive manufacturing (step S3). More precisely, the inclination wedge 80 is first manufactured, layer by layer, on the construction plate extending in the construction plane P, and the part 1 is manufactured in the continuity of the inclination wedge 80. In other words, during manufacture, the tilt wedge 80 and the part 1 form one and the same part, and are formed from the same material.

[0070] Given the addition of the tilt wedge 80 during step S2, during the manufacture of the wedge/part assembly in the vertical construction direction Z, the central axis X of the part 1 has an angle of inclination 0 with respect to the construction direction Z. Consequently, the aforementioned connection plane R, comprising the connection section S between the junction portion 42 and the flange 20, is also inclined by an angle P relative to the construction plane P. Thus, the connection between the junction portion 42 and the flange 20 does not take place in one layer, unlike the configuration illustrated in FIGS. 4A and 4B in the absence of tilt wedge 80, but in several layers. The connection between the junction portion 42 and the flange 20 is therefore progressive.

[0071] Figures 6A to 6D illustrate the formation of the connection section S between the junction portion 42 and the flange 20 during additive manufacturing. Given the inclination of the connection plane R, several layers are necessary to form this connection section S, in other words, to fill the gap I existing between the junction portion 42 and the flange 20 at this stage. of the manufacture of the part 1 . Figure 6A illustrates a connection section Sn to an n-layer of additive manufacturing. Figure 6B illustrates a connecting section Sn+1 to the next n+1 layer of additive manufacturing. Given the inclination of the connection plane R, the portion of the connection section Sn+1 formed at this layer n+1 can be supported, at least in part, on the material already formed during the previous layer n. This makes it possible to limit the phenomenon of subsidence, and therefore the presence of bumps on the final part. Similarly, Fig. 6C illustrates a section connecting Sn+2 to layer n+2, and Fig. 6D illustrates a section of Sn+3 connection to the next n+3 layer of additive manufacturing, each surface formed in one layer being able to rest on the surface formed in the previous layer.

[0072] Preferably, the number of layers necessary to completely form the connection section S is between 10 and 40. Preferably, the angle of inclination p and the elevation height £ are determined in such a way that the number of layers necessary to completely form the connecting section S is included in this interval.

It will be noted that the above description, with reference to FIGS. 3 to 6D, relates to the connection section S between the junction portion 42 and the flange 20. Nevertheless, this description is of course valid for the other surfaces of connection concerned by the problem described, in particular the connection sections S between the junction portion 32 and 52, and the flange 20.

[0074] When the manufacture of part 1 is completed, the tilting wedge 80 having made it possible to tilt part 1 during manufacture is removed (step S4). This removal can be carried out by machining, for example, by removing the quantity of material corresponding to the dimensions of the tilt wedge 80, thus making it possible to obtain the final part 1 having the desired dimensions, and corresponding to the digital model existing before the orientation step S2, in which the tilt wedge 80 had been added.

[0075] Figure 8 shows a digital model of a second example of part 1 'to be manufactured, on which the method according to the invention can be applied. In this example, the part 1′ to be manufactured is a bearing support of the SP5 NMA type, intended to be used in a turbojet engine, in particular at the level of the exhaust casing of an engine of the UHBR DD (“Ultra High Bypass Ratio Direct Drive”). The connection zones between walls inclined with respect to each other, and involving the same problems as part 1 of the first example, are located by circles in FIG. 8, and the corresponding connection sections S′ are also indicated. Although the present invention has been described with reference to specific embodiments, it is obvious that modifications and changes can be made to these examples without departing from the general scope of the invention as defined by the revendications. In particular, individual features of the different illustrated/mentioned embodiments can be combined in additional embodiments. Accordingly, the description and the drawings should be considered in an illustrative rather than restrictive sense.

Claims

[Claim 1] Method of manufacturing an aeronautical part by additive manufacturing, the part to be manufactured extending around a central axis (X) and comprising at least two walls (20, 42) inclined one with respect to the another and connected to each other via at least one connection section (S) included in a connection plane (R) perpendicular to the central axis (X), the method comprising:

- the supply of a digital model (1) of the part to be manufactured,

- the orientation of the digital model (1) with respect to a vertical construction direction (Z) of the part so that the central axis (X) of the part has an angle P between 0.1° and 1°, preferably between 0.3° and 0.8° relative to the direction of construction (Z),

- manufacturing of the part by additive manufacturing from the digital model (1) obtained at the orientation stage.

[Claim 2] Method according to claim 1, in which the workpiece is axisymmetric about the central axis (X), and the connecting section (S) extends according to an arc of a circle centered about the axis central (X).

[Claim 3] The method of claim 1 or 2, wherein the step of orienting the digital model (1) includes adding to the digital model a tilt wedge (80) between a construction plane (P ) horizontal and a plane (B) comprising a lower end (12) of the workpiece, so as to incline the central axis (X) by the angle P relative to the construction direction (Z) vertical.

[Claim 4] A method according to claim 3, wherein the tilt wedge (80) is fabricated from the same material as the workpiece, during additive manufacturing.

[Claim 5] A method according to claim 3 or 4, wherein the tilt wedge (80) is configured such that, in the plane (B) comprising the lower end (12) of the workpiece, a first radial end (14) of the workpiece has an elevation E relative to a second radial end (16) opposite the first radial end (14).

[Claim 6] A method according to claim 5, wherein the workpiece comprises a substantially cylindrical outer shell (10), the outer shell (10) comprising the lower end (12) and the first and second radial ends ( 14, 16), the first and the second radial end (14, 16) being diametrically opposite with respect to each other.

[Claim 7] A method according to claim 6, wherein s = Dxarctan(P), where D is the diameter of the outer shell (10) of the workpiece.

[Claim 8] A method according to any one of claims 3 to 7, comprising, after the manufacturing step, a step of removing the tilt wedge (80), in which the tilt wedge (80) used to tilt the part during its manufacture is removed, in order to obtain the final part.

[Claim 9] A method according to claim 8, wherein the removal of the tilt wedge (80) is accomplished by machining.

[Claim 10] A method according to any preceding claim, wherein the workpiece is a turbojet engine bearing support.